# Other Papers

## Working papers and unpublished versions of articles

"Extreme Agenda Setting Power in Dynamic Bargaining Games" (2018) with Zizhen Ma. We investigate a canonical model of bargaining with a fixed agenda setter, and we show that when players are impatient or the set of alternatives is one-dimesional, the equilibrium outcome from the static model obtains; but when players are patient and the alternatives are multidimensional, the equilibrium outcome typically converges to the ideal point of the agenda setter.

“Electoral Accountability and Responsive Democracy” (2017) with Cesar Martinelli. We analyze a canonical two-period model of elections in which politicians’ preferences and actions are imperfectly observed by voters, i.e., elections are subject to adverse selection and moral hazard. We establish existence of electoral equilibrium, and we give a characterization of equilibria. We show that as politicians become more office motivated, policy is responsive to voter preferences in the sense that the expected level of effort exerted by politicians in the first period becomes arbitrarily large.

“Lobbying and Policy Extremism in Repeated Elections” (2017) with Peter Bils and Gleason Judd. We investigate the effect of lobbying on policy choices in an infinite-horizon model of elections. We find that when the effectiveness of money is fixed, if office incentives become large, then policy choices converge to the median. However, if office incentives are fixed and the effectiveness of money becomes large, then polarized equilibria that exhibit arbitrarily extreme policy choices by all politician types can be supported. Here are some slides from a talk.

“Subgame-Perfect Equilibrium in Games with Almost Perfect Information: Dispensing with Public Randomization” (2017) with Paulo Barelli. Harris, Reny, and Robson (1995) show that correlated subgame perfect equilibrium exist in a general class of dynamic games. We show that when nature’s moves are atomless, every such equilibrium can be de-correlated: there is a payoff-equivalent subgame-perfect equilibrium of the original game. As a corollary, we obtain an existence result of He and Sun (2016) for subgame perfect equilibria in games with atomless moves by nature.

“Directional Equilibria” (2017) with Hun Chung. We propose a new solution concept (directional equilibrium) for the multidimensional spatial model. We establish connections to the core, Pareto optimality, and existence of directional equilibria, and we provide non-cooperative foundations. Here is a longer working paper with results on generic properties of directional equilibria, here are some slides from a longer talk, and here are slides from a shorter talk.

“The Political Economy of Dynamic Elections: A Survey and Some New Results” (2017) with Cesar Martinelli. This paper contains a survey and synthesis of the literature on electoral accountability, i.e., repeated elections in which politicians cannot commit their policy choices. We establish sets of conditions under which policy choices nevertheless reflect the preferences of the median voter. A shorter version with redacted proofs is published in *Journal of Economic Literature*, 2017, 55: 916--984.

“A Note on the Pareto Manifold in the Spatial Model of Politics” (2016) I provide sufficient conditions for the Pareto set to exhibit a manifold structure near a Pareto optimal alternative -- the analysis takes utility functions as given, rather than making genericity claims. I then investigate a natural parameterization of the Pareto manifold and the corresponding parameterized utilities. In contrast to Smale (1976), I do not assume an economic environment; rather, I consider a general model that includes the spatial model of politics as a special case.

“Multidimensional Tug of War” (2016) with Jacque Gao. We analyze a game in which players exert effort to pull a collective outcome in a multidimensional space in their preferred direction. We prove existence and uniqueness of equilibrium and characterize the outcome as risk aversion varies.

“Sequential Median Location” (2015) This short note shows that in sequential location games in one dimension with single-peaked preferences, if the order of location alternates between agents on one side of the median and the other, then the unique pure strategy subgame perfect equilibrium outcome is the median. The result extends to sequential play of any Condorcet consistent game and to mixed strategies.

“Choice-theoretic Solutions for Strategic Form Games” (2014) with Michel Le Breton. This is the continuation of an old project with Michel Le Breton in which we assume common knowledge of players’ choice sets, rather than mixed strategies. The approach allows for probability-free theories of how players resolve strategic uncertainty and generalizes known results for rationalizable strategies. Here is a working paper version with additional results on choice based on pessimistic conjectures.

“Markovian Elections” (2014) with Jean Guillaume Forand. We establish equilibrium existence and median voter results in a model of dynamic elections with an endogenously evolving state variable. The framework is quite general, and we give several examples of different types of political failure. Here are some slides from a talk.

“Dynamic Elections and the Limits of Accountability” (2014) with Jean Guillaume Forand.

“The State of Nature as a Spatial Contest” (2014) I model the state of nature as a spatial contest, in which the final outcome is a deterministic and continuous function of individual effort levels. I establish existence and uniqueness of equilibrium, I characterize the equilibrium of the game, and I perform comparative statics on the cost of effort and risk aversion of the players.

“Value Restriction, Median Voters, and the Core” (2013) I extend results on value restriction to general voting rules and synthesize forms of median voter theorems and representative voter theorems. For a more general analysis of social rationality, see “Preference Exclusions for Social Rationality,” *Social Choice and Welfare*, 46: 93--118.

"Limits of Acyclic Voting and Nash Implementation" (2012) An Arrovian result for acyclic social choice under the independence of irrelevant alternatives. This is version features a much shorter proof of a more general theorem; see the working paper for the case of four or more alternatives. Note the "throwback" typesetting, including typewriter math font; see the modern version, if you don’t like the old mimeograph style. Here are slides from a talk. A shorter version of this paper, without the Nash implementation results, is published in *Journal of Economic Theory*, 163: 658--683.

"Mixed Strategy Equilibrium and Deep Covering in Multidimensional Electoral Competition" (2006) with Matt Jackson. Here are some slides from a talk.

"Existence of Equilibria on Convex Sets" (2004) with Jeff Banks

"Robust Implementation" (2001) with Joanne Roberts.

"Non-cooperative Games Among Groups" (2001)

"Equilibrium Non-existence in a Model of Representative Democracy" (2001) with Arantxa Jarque-Llamazares.

"Equilibrium Equivalence Under Expected Plurality and Probability of Winning Maximization" (2000) Incomplete: one section missing.

"Implementing the Efficient Allocation of Pollution" (1999) with Joanne Roberts. This paper has been published (American Economic Review, 2002, 92:1070-1078), but the unpublished version contains an analysis of the model with incomplete information.

"Mixed Refinements of Shapley's Saddles and Weak Tournaments" (1999) with Michel Le Breton. This paper has been published (Social Choice and Welfare, 2001, 8:65-78), but the unpublished version contains a more comprehensive analysis of solutions of weak tournaments and an appendix with several additional examples.

"A Bargaining Model of Collective Choice" (1999) with Jeff Banks. This paper has been published (American Political Science Review, 2000, 94:73-88), but the unpublished version contains an appendix showing that our assumption of "limited shared weak preference" is satisfied in a variety of economic environments.

"Dominance-based Solutions for Strategic Form Games" (1998) with Michel Le Breton. Here are some slides from a talk.

"More Bogosity Results for Monotonic Social Choice Rules" (1995) with Tom Schwartz. From the archives: One of my unpublished "classics," related to some results in my paper "Limitations of Acyclic Voting and Implementation."